IVDemon Armor is the strongest armor for Dark KnightCecil, providing 9 Defense, 3 Magic Defense, and -10 Evasion. It can be bought for 3,000 gil at Fabul. In the 3D remakes, it remains largely the same, but loses the -10 Evasion penalty.

In the International version, it now provides 30 Defense, +5 Strength, and +3 Vitality, while still requiring the Heavy Armor 5 license to equip. It can now be bought for 4,700 gil at Mt Bur-Omisace, found at Barheim Passage (The Zevah Span) and Phon Coast (Cape Uahuk), or dropped from Darkmare or Bull Croc (3% chance).